Stimulus control equipment, stimulus control method, and stimulus presentation device

Abstract

One embodiment of the present invention is stimulus control equipment equipped with: an ultrasonic irradiation device that irradiates a stimulus presentation device with ultrasonic waves, said stimulus presentation device being provided with a passive sound absorbing material that absorbs the ultrasonic waves and emits heat, and a passive displacement body that is at least partially displaced upon reception of the ultrasonic waves; and a control unit that controls the operation of the ultrasonic irradiation device. The control unit controls the operation of the ultrasonic irradiation device to radiate the ultrasonic waves toward the sound absorbing material during a part of a prescribed unit period, and to radiate the ultrasonic waves toward the displacement body during another part of the unit period.

Description

Stimulus control device, stimulus control method, and stimulus presenter

[0001] The present invention relates to a stimulus control device, a stimulus control method, and a stimulus presenter.

[0002] With growing interest in haptic technology, there is a demand for lighter, more comfortable tactile displays. Passive tactile devices that do not require batteries or wiring have been proposed as lightweight, easy-to-use devices. The term "passive" refers to the ability to present stimuli to a target without the use of a power source or wiring. Ultrasound-driven devices are particularly promising, and a technology has been proposed that amplifies the radiation force of ultrasound using a lever mechanism to present forces of several hundred millinewtons and low-frequency vibrations of 2 to 30 Hz using a plastic device weighing a few grams (see Non-Patent Document 1). Another technology has also been proposed that presents thermal stimuli by irradiating ultrasound onto sound-absorbing materials such as cloth (see Non-Patent Document 2).

[0003] Morisaki et al., “Ultrasound-Driven Passive Haptic Actuator Based on Amplifying Radiation Force Using Simple Lever Mechanism,” SIGGRAPH Asia 2022, Emerging Technologies, 2022.Kamigaki et al., “Noncontact Thermal and Vibrotactile Display using Focused Airborne Ultrasound,” International Conference on Human Haptic Sensing and Touch Enabled Computer Applications (Eurohaptics), 2020.

[0004] Incidentally, to reproduce the tactile sensations of human skin or hot water, it is necessary to present both temperature and force, i.e., thermal and mechanical stimuli. However, until now, no technology has been proposed for presenting thermal and mechanical stimuli in ultrasonically driven passive tactile devices (which do not include power sources or wiring) as described above. Although structures for presenting mechanical and thermal stimuli have been proposed as described above, a method for simultaneously driving these stimuli within a practical acoustic power range (e.g., 10 W) remains unknown.

[0005] In view of the above circumstances, an object of the present invention is to provide a technology for presenting thermal and mechanical stimuli using a passive device driven by ultrasound.

[0006] One aspect of the present invention is a stimulus control device comprising: an ultrasonic irradiator that irradiates ultrasonic waves to a stimulus presenter that includes a sound-absorbing material that is passive and absorbs ultrasonic waves and releases heat; and a displacement body that is passive and is displaced at least partially when exposed to ultrasonic waves; and a control unit that controls the operation of the ultrasonic irradiator, wherein the control unit controls the operation of the ultrasonic irradiator so that ultrasonic waves are irradiated toward the sound-absorbing material during a portion of a predetermined unit period, and so that ultrasonic waves are irradiated toward the displacement body during another portion of the unit period.

[0007] One aspect of the present invention is a stimulus control method executed by a stimulus control device that includes an ultrasound irradiator that irradiates ultrasound onto a stimulus presenter that includes a sound-absorbing material that is passive and absorbs ultrasound and releases heat, and a displacement body that is passive and at least a portion of which is displaced when exposed to ultrasound, and a control unit that controls the operation of the ultrasound irradiator, wherein the control unit controls the operation of the ultrasound irradiator so that ultrasound is irradiated toward the sound-absorbing material during a portion of a predetermined unit period, and ultrasound is irradiated toward the displacement body during another portion of the unit period.

[0008] One aspect of the present invention is a stimulus presenter comprising a passive sound-absorbing material that absorbs ultrasound and releases heat, and a passive displacement body that is displaced at least in part when exposed to ultrasound.

[0009] The present invention makes it possible to present thermal and mechanical stimuli passively driven by ultrasound.

[0010] 1 is an explanatory diagram illustrating a stimulation system according to an embodiment. 2 is an explanatory diagram illustrating an example of the configuration of a stimulation system according to an embodiment. 3 is an explanatory diagram illustrating a first example of control by time-sharing control processing according to an embodiment. 4 is an explanatory diagram illustrating a second example of control by time-sharing control processing according to an embodiment. 5 is a first diagram illustrating an example of an experimental result according to an embodiment. 6 is a second diagram illustrating an example of an experimental result according to an embodiment. 7 is a diagram illustrating a more detailed example of the hardware configuration of a stimulation control device 1 according to an embodiment. 8 is a diagram illustrating an example of the flow of processing executed by the stimulation control device 1 according to an embodiment. 9 is a diagram illustrating an example of the configuration of a stimulation system according to a modified example.

[0011] 1 is an explanatory diagram illustrating a stimulation system 100 according to an embodiment. The stimulation system 100 includes a stimulation control device 1 and a stimulation presenter 2. The stimulation control device 1 includes an ultrasound irradiator 10, which irradiates the stimulation presenter 2 with ultrasound.

[0012] More specifically, the stimulation control device 1 includes an ultrasound irradiator 10 and a control unit 11 connected via a bus and including a processor 91 such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an NPU (Neural Network Processing Unit), and a memory 92. The ultrasound irradiator 10 is controlled by the control unit 11 to irradiate the stimulation presenter 2 with ultrasound.

[0013] The ultrasonic irradiator 10 is, for example, a collection of ultrasonic transducers. Therefore, the ultrasonic irradiator 10 is, for example, an ultrasonic phased array. The ultrasonic phased array can change the intensity and propagation destination of the radiated ultrasonic waves. Specifically, for each ultrasonic transducer included in the ultrasonic phased array, the intensity and phase of the radiated ultrasonic waves change, thereby changing the intensity, waveform, and propagation destination of the ultrasonic waves radiated by the ultrasonic phased array. Note that changing the propagation destination of the ultrasonic waves specifically means changing the position of the focal point of the ultrasonic waves. Furthermore, the distribution of the presented sound pressure does not have to be a focal point; specifically, multifocal or plane waves may be presented.

[0014] The intensity of ultrasonic waves may be any quantity that indicates the energy carried by the ultrasonic waves. Therefore, the intensity of ultrasonic waves may be, for example, the energy of the ultrasonic waves, or, if the waveform of the ultrasonic waves is a sine wave, the amplitude of the sine wave. Furthermore, if the waveform of the ultrasonic waves is a non-sine wave such as a Gaussian function, the intensity of ultrasonic waves may be the maximum amplitude of the waveform.

[0015] The stimulus presenter 2 includes a sound-absorbing material 21 and a displacement body 22. The sound-absorbing material 21 is passive, absorbing ultrasonic waves and releasing heat. Note that "passive" means that it is capable of presenting a stimulus to a presentation target without using a power source or wiring. "Passive" means that it is capable of presenting a stimulus to a presentation target without using a power source or wiring.

[0016] The sound-absorbing material 21 is a passive material that absorbs ultrasonic waves and releases heat. The sound-absorbing material 21 may be any passive material that absorbs ultrasonic waves and releases heat, such as cloth. Cloth is an example of a passive material that is driven by ultrasonic waves, as it can absorb ultrasonic waves and release heat without requiring a power source or wiring.

[0017] The displacing body 22 is a passive body that is displaced at least in part when it receives ultrasonic waves. If there is an object at the destination of displacement of the displacing body 22, the object and the displacing body 22 come into contact. This contact provides a mechanical stimulus to the object at the destination of displacement. Therefore, when the stimulus presenter 2 is attached to a stimulus presentation target such as a person or animal, the stimulus presenter 2 irradiated with ultrasonic waves by the stimulus control device 1 presents heat and mechanical stimuli to the presentation target. The mechanical stimulus is specifically a force.

[0018] The displacement body 22 is, for example, a passive vibrator that vibrates when exposed to ultrasound. When the displacement body 22 is the vibrator, the stimulation caused by the vibration of the vibrator is an example of a mechanical stimulation. When the displacement body 22 is the vibrator, the magnitude of the displacement is the magnitude of the amplitude of the vibration.

[0019] The displacing body 22 may be one that applies a stimulus to a presentation target using, for example, the principle of a lever. Specifically, a device that applies a stimulus to a presentation target using the principle of a lever is a passive device that has a portion that functions as a fulcrum, a portion that functions as a point of application, and a portion that functions as a point of force, and the presentation target is located at the point of application where ultrasound is irradiated. As long as ultrasound is irradiated at the position of the point of application, the position of the point of force may be, for example, the focus of ultrasound.

[0020] When ultrasound is applied to the point of application, the force of the ultrasound is applied to the point of application, displacing the position of the point of application. As a result, a force is applied to the presentation target located at the point of application's displacement. This force applied to the presentation target is an example of a mechanical stimulus. A passive device that uses the principle of leverage to stimulate a presentation target is an example of an ultrasonically driven passive device, as it can receive ultrasound and present mechanical stimuli without using a power source or wiring.

[0021] If the displacement body 22 is a passive body that applies a stimulus to the presentation object using the principle of leverage, it is sufficient that the displacement body 22 be able to passively apply a stimulus to the presentation object using the principle of leverage, and therefore the displacement body 22 may be a rigid body of a predetermined strength, for example, the size of a plastic rod.

[0022] 2 is an explanatory diagram illustrating an example of the configuration of the stimulation system 100 according to the embodiment. More specifically, FIG. 2 illustrates an example of the configuration of a stimulation control device 1 and a stimulation presenter 2.

[0023] 2 shows displacement bodies 22-a and 22-b as examples of displacement body 22. Displacement body 22-a is an example of displacement body 22 after displacement due to ultrasonic irradiation. Displacement body 22-b is an example of displacement body 22, and is an example of displacement body 22 that becomes displacement body 22-a after displacement.

[0024] 2, the displacement body 22 is a passive body that applies a stimulus to the presentation target 9 using the principle of a lever. FIG. 2 shows that the sound absorbing material 21 and the displacement body 22 are attached to the finger of the presentation target 9.

[0025] Point P1 in Fig. 2 is an example of the point of action, and point P2 is an example of the point of force. Region D1 in Fig. 2 indicates the spatial region to which ultrasound is irradiated. In the example of Fig. 2, point P2 is located within region D1, so that irradiation of the displacing body 22 with ultrasound displaces point P1, and a mechanical stimulus is applied to the presentation target.

[0026] Image G1 in FIG. 2 shows the heat emitted by the sound absorbing material 21 as a result of the sound absorbing material 21 being irradiated with ultrasonic waves.

[0027] 2 also shows an example of the configuration of the ultrasonic irradiator 10. The ultrasonic irradiator 10 includes a plurality of ultrasonic transducers 101. Each ultrasonic transducer 101 is controlled by a control unit 11.

[0028] Returning to the explanation of Fig. 1, the control unit 11 controls the operation of the ultrasonic irradiator 10 and changes the intensity, waveform, and propagation destination of the ultrasonic waves emitted by the ultrasonic irradiator 10. The control unit 11 performs time-sharing control processing. The time-sharing control processing is processing for controlling the operation of the ultrasonic irradiator 10 so that ultrasonic waves are irradiated toward the sound-absorbing material 21 during a part of a unit period, which is a predetermined period, and ultrasonic waves are irradiated toward the displacement body 22 during another part of the unit period.

[0029] Incidentally, irradiating ultrasonic waves toward the sound-absorbing material 21 means radiating ultrasonic waves so that the focal point of the ultrasonic waves is located on the sound-absorbing material 21. Irradiating ultrasonic waves toward the displacement body 22 means radiating ultrasonic waves so that the focal point of the ultrasonic waves is located on the displacement body 22.

[0030] By the time-sharing control process, for example, ultrasonic waves are irradiated toward the displacement body 22 for 1 / 3 of the unit period, and ultrasonic waves are irradiated toward the sound-absorbing material 21 for the remaining period of the unit period (i.e., 2 / 3 of the unit period).

[0031] 3 is an explanatory diagram illustrating a first example of control by time-sharing control processing in an embodiment. FIG. 3 shows a state in which ultrasonic waves are irradiated from the ultrasonic irradiator 10 to the sound-absorbing material 21 and the displacement body 22 at a duty ratio of 0.5 by executing the time-sharing control processing.

[0032] Specifically, ultrasonic waves are irradiated onto the displacement body 22 from the time origin to time t1, ultrasonic waves are irradiated onto the sound-absorbing material 21 from time t1 to time t2, and ultrasonic waves are irradiated onto the displacement body 22 from time t2 to time t3. The length of time from the time origin to time t1, the length of time from time t1 to time t2, and the length of time from time t2 to time t3 are the same.

[0033] The period from the time origin to time t2 is an example of a unit period.

[0034] Fig. 3 also shows that a rectangular wave is irradiated onto both the sound-absorbing material 21 and the displacement body 22. Fig. 3 also shows that there is a difference in the maximum instantaneous value of energy between the sound-absorbing material 21 and the displacement body 22. Specifically, Fig. 3 shows that the maximum instantaneous value A2 of the displacement body 22 is smaller than the maximum instantaneous value A1 of the sound-absorbing material 21.

[0035] 4 is an explanatory diagram illustrating a second example of control by the time-division control process in the embodiment. FIG. 4 shows a state in which ultrasonic waves are irradiated from the ultrasonic irradiator 10 to the sound-absorbing material 21 and the displacement body 22 at a duty ratio of 0.1 by executing the time-division control process.

[0036] Specifically, ultrasonic waves are irradiated onto the displacement body 22 from the time origin to time t4, ultrasonic waves are irradiated onto the sound-absorbing material 21 from time t4 to time t5, and ultrasonic waves are irradiated onto the displacement body 22 from time t5 to time t6. The length of time from time t1 to time t2 is nine times the length of time from the time origin to time t1.

[0037] The period from the time origin to time t6 is an example of a unit period.

[0038] Fig. 4 also shows that a rectangular wave is irradiated onto both the sound-absorbing material 21 and the displacement body 22. Fig. 4 also shows that the maximum instantaneous energy values ​​are the same for the sound-absorbing material 21 and the displacement body 22. Specifically, Fig. 4 shows that the maximum instantaneous energy value A4 of the displacement body 22 is the same as the maximum instantaneous energy value A3 of the sound-absorbing material 21.

[0039] Even when the duty ratio is 0.9, the maximum instantaneous value of the displaceable body 22 and the maximum instantaneous value of the sound-absorbing material 21 do not necessarily have to be the same. The maximum instantaneous value of the displaceable body 22 may be smaller or larger than the maximum instantaneous value of the sound-absorbing material 21. Furthermore, when the duty ratio is 0.1, the maximum instantaneous value of the displaceable body 22 and the maximum instantaneous value of the sound-absorbing material 21 may be the same, or the maximum instantaneous value of the displaceable body 22 may be larger than the maximum instantaneous value of the sound-absorbing material 21. The instantaneous values ​​shown in FIGS. 3 and 4 are all examples.

[0040] The duty ratio may be any duty ratio and does not necessarily have to be 0.5 or 0.1. Regardless of the duty ratio, the maximum instantaneous value of the displacement body 22 and the maximum instantaneous value of the sound-absorbing material 21 may be the same or different.

[0041] 3 and 4, a rectangular wave is applied to both the sound absorbing material 21 and the displacement body 22, but the waveform of the ultrasonic wave does not necessarily have to be a rectangular wave. For example, the waveform may be a Gaussian waveform. The waveforms in FIGS. 3 and 4 are both examples.

[0042] <Effects of Time-Division Control Processing> The effects of time-division control processing will be described. To cause the stimulus presentation device 2 to present heat and mechanical stimuli, a technique for continuously irradiating the sound-absorbing material 21 and the displaceable body 22 with ultrasound simultaneously (hereinafter referred to as "space-division control") may be used. That is, to cause the stimulus presentation device 2 to present heat and mechanical stimuli, a technique for simultaneously positioning the focus of ultrasound on the sound-absorbing material 21 and the displaceable body 22 may be used. Even in this case, the sound-absorbing material 21 can radiate heat, and the displaceable body 22 can provide a mechanical stimulus to the presentation target.

[0043] As an application example of space division control, consider a case where, of the amount of energy emitted by the ultrasonic radiator 10 in a unit period, Pa1% is radiated to the sound absorbing material 21 and Pa2% is radiated to the displacement body 22. If the ultrasonic radiator 10 always radiates ultrasonic waves simultaneously to the sound absorbing material 21 and the displacement body 22 with this energy distribution, the displacement of the displacement body 22 will continue to be a constant displacement corresponding to the energy of Pa2% while it is receiving ultrasonic waves.

[0044] Consider a situation in which time-division control processing is executed. Assume that ultrasonic waves are irradiated onto the sound-absorbing material 21 for a period of Pa3% of the unit period, and onto the displaceable body 22 for the remaining period of Pa4%. Pa4 is smaller than Pa2. Furthermore, the total amount of energy radiated by the ultrasonic radiator 10 in the unit period is equal to the total amount in the case of space-division control. In this case, the displaceable body 22 is irradiated with energy of Pa4%, which is less than the energy in the case of space-division control.

[0045] However, the deformable body 22 can provide a mechanical stimulus to the presentation target that is Pa4 / Pa2 or more times stronger. The reason for this will be explained below.

[0046] One of the differences between the events occurring in the case of time-division control processing and the events occurring in the case of space-division control is whether or not the magnitude of the displacement attenuates over time. In the case of time-division control processing and the case of space-division control, the displacement of the displacing body 22 at the moment it receives energy can actually be about the same.

[0047] As an example, a comparison will be made between an ultrasonic pulse wave having a maximum value M and a CW (Continuous Wave) wave having a maximum value M. In this case, the displacement of the displacing body 22 is greatest at the timing when the amplitude of the wave that has reached the displacing body 22 reaches its maximum value M. Therefore, the displacement that occurs at this timing is about the same whether it is caused by a pulse wave or a CW wave. Of course, unlike a CW wave, the displacement caused by a pulse wave attenuates over time. However, as an instantaneous value, the displacement caused by the pulse wave and the displacement caused by the CW wave are about the same.

[0048] Furthermore, a strong mechanical stimulus for a presentation target does not necessarily have to be continuous, but can be a momentary strong mechanical stimulus. Therefore, from the perspective of presenting a mechanical stimulus to a presentation target, it does not actually have to be a continuous mechanical stimulus by space-division control, but can be a temporary mechanical stimulus by time-division control processing.

[0049] In this way, by executing the time-division control process, it is possible to reduce the energy required to apply a mechanical stimulus. As a result, it is possible to increase the energy applied to the sound-absorbing material 21. Of course, the amount of energy applied to the sound-absorbing material 21 may be the same as in the case of the space-division control. In this case, the total amount of energy radiated by the ultrasound irradiator 10 is reduced, and therefore the energy consumption required to present a stimulus to the presentation target is reduced.

[0050] <Experimental Results> The occurrence of the above-mentioned effects was confirmed through experiments, and an example of the experimental results will now be described. In the experiment, a square wave with a predetermined duty ratio was irradiated onto the sound-absorbing material 21 by executing a time-sharing control process. In the experiment, the heat radiated from the sound-absorbing material 21 was measured using a thermocouple. In the experiment, the magnitude of the displacement of the displacement body 22 was further estimated through a vibration characteristics simulation using the measurement results from the thermocouple.

[0051] FIG. 5 is a first diagram showing an example of experimental results in an embodiment. More specifically, FIG. 5 shows the change in temperature measured by the thermocouple over time when the duty ratio was 0.5, 0.7, and 0.9. In the experiment, the ultrasonic frequency was 5 Hz. The horizontal axis of FIG. 5 represents time, and the vertical axis represents temperature. The horizontal axis is in seconds, and the vertical axis is in degrees Celsius.

[0052] 5, "Duty=0.5" means that the duty ratio in the experiment was 0.5. A duty ratio of 0.5 in the experiment means that, due to time-sharing control processing, ultrasonic waves were irradiated onto the sound-absorbing material 21 for 50% of the unit period, and onto the displacement body 22 for 50% of the unit period.

[0053] 5, "Duty=0.7" means that the duty ratio in the experiment was 0.7. A duty ratio of 0.7 in the experiment means that, due to the time-sharing control process, ultrasonic waves were irradiated onto the sound-absorbing material 21 for 70% of the unit period and onto the displacement body 22 for 30% of the period.

[0054] 5, "Duty=0.9" means that the duty ratio in the experiment was 0.9. A duty ratio of 0.9 in the experiment means that, due to the time-sharing control process, ultrasonic waves were irradiated onto the sound-absorbing material 21 for 90% of the unit period, and onto the displacement body 22 for 10% of the unit period.

[0055] The results in Figure 5 show that the temperature increases over time, and that the higher the duty ratio, the faster the rate of temperature increase.

[0056] 5 shows that the heating rate is 3.49 degrees / second or more when the duty ratio is 0.7 and 0.9, indicating that the stimulation system 100 can rapidly deliver heat to the target.

[0057] FIG. 6 is a second diagram showing an example of experimental results in an embodiment. The horizontal axis of FIG. 6 represents "Modulation frequency," and the vertical axis represents "Amplitude at modulation frequency." The horizontal axis is in Hz. The vertical axis is in Newton. "Modulation frequency" is defined as the switching frequency of the ultrasonic focal position, and is the reciprocal of the unit period in ultrasonic irradiation. For example, a modulation frequency of 5 Hz means that the focal position moves between the sound-absorbing material 21 and the displacement body 22 at 5 Hz. In this case, a 5 Hz rectangular wave is input to both the sound-absorbing material 21 and the displacement body 22.

[0058] The definition of "Amplitude at modulation frequency" is that the vibration amplitude obtained by simulation is Fourier transformed and only the modulation frequency component is extracted from it. For example, in Figure 6, the value of Amplitude at modulation frequency when the modulation frequency is 5 Hz, that is, the value on the vertical axis at 5 Hz on the horizontal axis, is the amplitude (force) of the 5 Hz component of the vibration waveform obtained by simulation.

[0059] "Sin" in FIG. 6 refers to amplitude modulation with a sine wave, and is plotted for comparison as the most basic pattern in vibration presentation. Here, amplitude modulation with a sine wave means changing the power of ultrasound at a fixed focal point. For example, when performing sine wave modulation at 5 Hz, a 5 Hz vibration is applied to the displacement body 22. "Duty = 0.5" in FIG. 6 has the same meaning as "Duty = 0.5" in FIG. 5, "Duty = 0.3" has the same meaning as "Duty = 0.7" in FIG. 5, and "Duty = 0.1" has the same meaning as "Duty = 0.9" in FIG. 5.

[0060] 6 shows that even when "duty = 0.1", the maximum value of "Amplitude at modulation frequency" is 63% or more of the maximum value of "Amplitude at modulation frequency" when "duty = 0.5". The case of "duty = 0.1" means that ultrasonic waves are irradiated to the displacement body 22 for only 10% of the period.

[0061] Therefore, if we simply compare the irradiated energy, it is estimated that the magnitude of the mechanical stimulus when "duty = 0.1" is 20% or less of that when "duty = 0.5". However, the experimental results showed a value of 63%, which is more than three times 20%. In this way, the experimental results show that when comparing ultrasound waves with different duty ratios, the difference in the magnitude of the mechanical stimulus due to differences in duty ratio is smaller than the difference in the ratio indicated by the duty ratio.

[0062] 7 is a diagram showing a more detailed example of the hardware configuration of the stimulus control device 1 according to an embodiment. The stimulus control device 1 includes a control unit 11 having a processor 91 and a memory 92 connected via a bus, and executes a program. By executing the program, the stimulus control device 1 functions as a device including an ultrasound irradiator 10, the control unit 11, an interface unit 12, and a storage unit 13.

[0063] More specifically, the processor 91 reads out a program stored in the storage unit 13 and stores the read out program in the memory 92. When the processor 91 executes the program stored in the memory 92, the stimulation control device 1 functions as a device including the ultrasound irradiator 10, the control unit 11, the interface unit 12, and the storage unit 13.

[0064] The control unit 11 controls the operation of each functional unit included in the stimulation control device 1. The control unit 11 executes, for example, a time-sharing control process. The control unit 11 acquires, for example, information stored in the memory unit 13. Specifically, the process of acquiring the information stored in the memory unit 13 is reading.

[0065] The interface unit 12 includes a communication interface for connecting the stimulation control device 1 to an external device. The interface unit 12 communicates with the external device via a wired or wireless connection.

[0066] The interface unit 12 may be configured to include input devices such as a mouse, a keyboard, a touch panel, etc. The interface unit 12 may be configured as an interface that connects these input devices to the stimulation control device 1. In this way, the interface unit 12 accepts input of various information to the stimulation control device 1 via the input devices, either wired or wireless.

[0067] The interface unit 12 outputs, for example, various types of information. The interface unit 12 includes a display device such as a CRT (Cathode Ray Tube) display, a liquid crystal display, or an organic EL (Electro-Luminescence) display. The interface unit 12 may be configured as an interface that connects these display devices to the stimulation control device 1. The interface unit 12 outputs, for example, information input to the interface unit 12.

[0068] The storage unit 13 is configured using a computer-readable storage medium device (non-transitory computer-readable recording medium) such as a magnetic hard disk device or a semiconductor storage device. The storage unit 13 stores various information related to the stimulation control device 1. The storage unit 13 stores, for example, various information generated by the operation of the control unit 11. The storage unit 13 stores, for example, information acquired by the interface unit 12.

[0069] 8 is a diagram showing an example of a flow of processing executed by the stimulus control device 1 according to the embodiment. The control unit 11 executes a time-sharing control process (step S101). As a result, heat and mechanical stimuli are presented to the presentation target.

[0070] The stimulus control device 1 configured in this manner includes a control unit 11 that executes time-sharing control processing. Therefore, the stimulus control device 1 can present thermal and mechanical stimuli using passive devices driven by ultrasound.

[0071] (Modification) The control unit 11 may change the intensity, waveform, or destination of the ultrasonic waves emitted by the ultrasonic irradiator 10 based on the irradiation destination information. The irradiation destination information is information indicating the positions or orientations of the sound-absorbing material 21 and the displacement body 22 as seen from the ultrasonic irradiator 10.

[0072] 2, when the sound absorbing material 21 and the displacement body 22 are attached to the finger of the presentation target, the positions and orientations of the sound absorbing material 21 and the displacement body 22 change in accordance with the movement of the finger. In such a case, the control unit 11 is more likely to be able to present a stimulus to the presentation target by changing the strength, waveform, or propagation destination of the ultrasound in accordance with the change in the position or orientation of the sound absorbing material 21 and the displacement body 22 as seen from the ultrasound irradiator 10 than by not making any changes.

[0073] Therefore, the control unit 11 may change the intensity, waveform, or propagation destination of the ultrasound waves emitted by the ultrasound irradiator 10 based on the irradiation destination information. Specifically, the control unit 11 determines the intensity, waveform, or propagation destination of the ultrasound waves based on the irradiation destination information using information (hereinafter referred to as "relationship information") indicating the relationship between the positions or orientations of the sound absorbing material 21 and the displaceable body 22 as viewed from the ultrasound irradiator 10 and the intensity, waveform, or propagation destination of the ultrasound waves. The control unit 11 causes the ultrasound irradiator 10 to emit ultrasound waves with the determined intensity, waveform, or propagation destination. In this way, the control unit 11 changes the intensity, waveform, or propagation destination of the ultrasound waves emitted by the ultrasound irradiator 10 based on the irradiation destination information.

[0074] The relationship information may be, for example, a data table that defines the relationship between the positions or orientations of the sound-absorbing material 21 and the displaceable body 22 as viewed from the ultrasound irradiator 10 and the strength, waveform, or propagation destination of the ultrasound. The relationship information may be, for example, a predetermined function in which the positions or orientations of the sound-absorbing material 21 and the displaceable body 22 as viewed from the ultrasound irradiator 10 are used as independent variables and the strength, waveform, or propagation destination of the ultrasound is used as a dependent variable. The relationship information may be a mathematical model that has been trained in advance by machine learning, and that estimates the strength, waveform, or propagation destination of the ultrasound based on the positions or orientations of the sound-absorbing material 21 and the displaceable body 22 as viewed from the ultrasound irradiator 10.

[0075] The irradiation destination information may be obtained by any technology that can acquire the positions or orientations of the sound-absorbing material 21 and the displaceable body 22. For example, the irradiation destination information may be obtained based on a time series of photographs taken by a camera of the ultrasound irradiator 10, the sound-absorbing material 21, and the displaceable body 22. In such a case, the time series of photographs indicates changes in the positions or orientations of the sound-absorbing material 21 and the displaceable body 22 as seen from the ultrasound irradiator 10, and therefore the irradiation destination information can be obtained based on the time series of photographs.

[0076] Regarding the positions of the sound absorbing material 21 and the displacement body 22, for example, if a GPS (Global Positioning System) transmitter is attached to the sound absorbing material 21 and the displacement body 22, position information of the sound absorbing material 21 and the displacement body 22 as seen from the ultrasound irradiator 10 may be obtained by the GPS. Note that if the position of the ultrasound irradiator 10 does not change, it is not necessary to attach a GPS oscillator to the ultrasound irradiator 10, but if the position of the ultrasound irradiator 10 changes, a GPS oscillator may also be attached to the ultrasound irradiator 10.

[0077] When the stimulation system 100 is used so that the position and posture of the sound absorbing material 21 and the displaceable body 22 do not change as viewed from the ultrasound radiator 10, it is not necessary to use the irradiation destination information.

[0078] Note that the control unit 11 may acquire the irradiation destination information in any manner as long as it is possible to acquire the irradiation destination information, but for example, the control unit 11 may acquire the irradiation destination information transmitted from the transmitter of the irradiation destination information via the interface unit 12. Furthermore, the control unit 11 may itself perform calculations based on the image capture results of the above-described camera to acquire the irradiation destination information from the image capture results. In this case, the control unit 11 acquires the image capture results from the camera via the interface unit 12.

[0079] 9 is a diagram showing an example of the configuration of a stimulation system 100a according to a modified example. The stimulation system 100a differs from the stimulation system 100 in that it includes a camera 3. The camera 3 is a camera that captures images of the sound-absorbing material 21 and the deformable body 22. In the stimulation system 100a, the control unit 11 acquires irradiation destination information based on the image capture results of the camera 3.

[0080] When acquiring irradiation destination information based on the image capture results of the camera 3, for example, segmentation is performed on the image capture results of the camera 3 to obtain information indicating where in the image the images of the sound absorbing material 21 and the displaceable body 22 are located. Next, the positions and orientations of the sound absorbing material 21 and the displaceable body 22 are estimated based on information indicating the values ​​of the internal parameters and external parameters of the camera 3, information indicating the position and orientation of the ultrasound irradiator 10, and the segmentation results.

[0081] The stimulation control device 1 may be implemented using a plurality of information processing devices connected to each other via a network so as to be able to communicate with each other. In this case, the processes executed by the control unit 11 may be distributed among the plurality of information processing devices.

[0082] Note that all or part of the functions of the control unit 11, the interface unit 12, and the storage unit 13 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The program may be recorded on a computer-readable recording medium. Examples of computer-readable recording media include portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. The program may be transmitted via a telecommunications line.

[0083] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0084] REFERENCE SIGNS LIST 100, 100a...Stimulation system, 1...Stimulation control device, 2...Stimulation presenter, 3...Camera, 10...Ultrasound irradiator, 11...Control unit, 12...Interface unit, 13...Storage unit, 21...Sound absorbing material, 22, 22-a, 22-b...Displacement body, 101...Ultrasonic transducer, 91...Processor, 92...Memory

Claims

1. A stimulus control device comprising: an ultrasound irradiator that irradiates ultrasound to a stimulus presenter having a sound-absorbing material that is passive and absorbs ultrasound and releases heat, and a displacement body that is passive and at least a portion of which is displaced when exposed to ultrasound; and a control unit that controls the operation of the ultrasound irradiator, wherein the control unit controls the operation of the ultrasound irradiator to irradiate ultrasound toward the sound-absorbing material during a portion of a predetermined unit period, and to irradiate ultrasound toward the displacement body during another portion of the unit period.

2. The stimulus control device of claim 1, wherein the control unit controls the operation of the ultrasound irradiator based on irradiation destination information, which is information indicating the respective positions or orientations of the sound-absorbing material and the displacement body as viewed from the ultrasound irradiator.

3. A stimulus control method executed by a stimulus control device including an ultrasonic irradiator that irradiates ultrasonic waves to a stimulus presenter including a sound-absorbing material that is passive and absorbs ultrasonic waves and releases heat, and a displacement body that is passive and at least a portion of which is displaced when exposed to ultrasonic waves, and a control unit that controls the operation of the ultrasonic irradiator, the stimulus control method having a control step in which the control unit controls the operation of the ultrasonic irradiator so that ultrasonic waves are irradiated toward the sound-absorbing material during a portion of a predetermined unit period, and ultrasonic waves are irradiated toward the displacement body during another portion of the unit period.

4. A stimulus presenter comprising: a passive sound-absorbing material that absorbs ultrasonic waves and releases heat; and a passive displacement body that is displaced at least in part when exposed to ultrasonic waves.

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